<!doctype html>
<html lang="en">
	<head>
		<title>three.js canvas - particles - random</title>
		<meta charset="utf-8">
		<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
		<style>
			body {
				background-color: #000000;
				margin: 0px;
				overflow: hidden;
			}

			a {
				color:#0078ff;
			}
		</style>
	</head>
	<body>

		<script src="../build/Three.js"></script>

		<script src="js/Stats.js"></script>

		<script>

			var container, stats;
			var camera, scene, renderer, group, particle;
			var mouseX = 0, mouseY = 0;

			var windowHalfX = window.innerWidth / 2;
			var windowHalfY = window.innerHeight / 2;

			init();
			animate();

			function init() {

				container = document.createElement( 'div' );
				document.body.appendChild( container );

				camera = new THREE.PerspectiveCamera( 75, window.innerWidth / window.innerHeight, 1, 3000 );
				camera.position.z = 1000;

				scene = new THREE.Scene();

				scene.add( camera );

				var PI2 = Math.PI * 2;
				var program = function ( context ) {

					context.beginPath();
					context.arc( 0, 0, 1, 0, PI2, true );
					context.closePath();
					context.fill();

				}

				group = new THREE.Object3D();
				scene.add( group );

				for ( var i = 0; i < 1000; i++ ) {

					particle = new THREE.Particle( new THREE.ParticleCanvasMaterial( { color: Math.random() * 0x808008 + 0x808080, program: program } ) );
					particle.position.x = Math.random() * 2000 - 1000;
					particle.position.y = Math.random() * 2000 - 1000;
					particle.position.z = Math.random() * 2000 - 1000;
					particle.scale.x = particle.scale.y = Math.random() * 10 + 5;
					group.add( particle );
				}

				renderer = new THREE.CanvasRenderer();
				renderer.setSize( window.innerWidth, window.innerHeight );
				container.appendChild( renderer.domElement );

				stats = new Stats();
				stats.domElement.style.position = 'absolute';
				stats.domElement.style.top = '0px';
				container.appendChild( stats.domElement );

				document.addEventListener( 'mousemove', onDocumentMouseMove, false );
				document.addEventListener( 'touchstart', onDocumentTouchStart, false );
				document.addEventListener( 'touchmove', onDocumentTouchMove, false );
			}

			//

			function onDocumentMouseMove( event ) {

				mouseX = event.clientX - windowHalfX;
				mouseY = event.clientY - windowHalfY;
			}

			function onDocumentTouchStart( event ) {

				if ( event.touches.length == 1 ) {

					event.preventDefault();

					mouseX = event.touches[ 0 ].pageX - windowHalfX;
					mouseY = event.touches[ 0 ].pageY - windowHalfY;
				}
			}

			function onDocumentTouchMove( event ) {

				if ( event.touches.length == 1 ) {

					event.preventDefault();

					mouseX = event.touches[ 0 ].pageX - windowHalfX;
					mouseY = event.touches[ 0 ].pageY - windowHalfY;
				}
			}

			//

			function animate() {

				requestAnimationFrame( animate );

				render();
				stats.update();

			}

			function render() {

				camera.position.x += ( mouseX - camera.position.x ) * 0.05;
				camera.position.y += ( - mouseY - camera.position.y ) * 0.05;
				camera.lookAt( scene.position );

				group.rotation.x += 0.01;
				group.rotation.y += 0.02;

				renderer.render( scene, camera );

			}

		</script>
	</body>
</html>
